1. Field of the Invention
The present invention relates to a two-dimensional fluorescent densitometry for measuring a specimen plate having a specimen spot such as phospholipide two-dimensionally developed and fluorescent-labelled on a TLC plate (thin film chromatography plate).
2. Description of the Prior Art
As a two-dimensional densitometer for measuring a specimen developed on the TLC plate, there is a densitometer of flying spot system which scans a measuring light in a reciprocating direction on the TLC plate and moves the TLC plate in a direction perpendicularly intersecting thereto to effect measurement.
The conventional densitometry measures the absorbancy from the reflective light and transmissive light of the measuring light caused by the specimen.
According to the flying spot system, a luminous flux is limited by a helical slit Sr whose distance from the center uniformly changes and a fixed slit Sfix extending radially of a slit disk 24 having said helical slit Sr and combined with said helical slit Sr, and the luminous flux on a specimen surface is laterally shaken by the reciprocating rotational motion of the helical slit Sr. In the case where the luminous flux is shaken on the specimen surface, the luminous flux has a so-called locality in which intensity differs with locations in the scanning direction. It is considered that the luminous flux has the locality due to the causes such as unevenness of width of a groove hole of the helical slit Sr, individuality of the optical system, particularly distribution of intensities of light irradiated on the fixed slit Sfix or changes in quantity of incident light to a detector due to an inclination of a light path when the luminous flux is shaken laterally.
In such a locality as described, it is possible for the densitometry for measuring the absorbancy of reflective light or transmissive light from the specimen to extract a part of the irradiated light by a half mirror or the like to monitor it.
As a densitometry, there can be considered a fluorescent mapping densitometer for fluorescent-labelling a specimen component developed on a specimen plate. The specimen component is fluorescent-labelled, and the specimen component is excited by an excitation light to excite the specimen component of which fluorescence is measured, whereby measurement with high sensitivity as compared with the conventional method for measuring the absorbancy can be carried out. However, the fluorescent mapping densitometry cannot correct the locality by the conventional system.